Centrifugal abrading machine



June 18, 1940. a. c. TURNBULL GENTRIFUGAL ABRADING MACHINE Original Filed Feb. 5, 1934 2 Sheets-Sheet 1 BY r 4; ATTORNEY June 18, 1940. D. c. TURNBULL 2,204,635

' CENTRIFUGAL ABRADING MACHINE I Original Filed Feb. 5, 1934 2 Sheets-Sheei 2 INVENTOR ,4 ATTORNEY Patented June 18, 1940 PATENT OFFICE CENTRIFUGAL ABRADING MACHINE David 0. Turnbull, Mishawaka, Ind., assignor to The American Foundry Equipment Company, -Misliawaka, Ind., a corporation of Delaware Original application February 5, 1934, Serial No. 709,727. Divided and this application August 4, 1938, Serial No. 222,961

12 Claims.

This invention relates to centrifugal abrading machines and more particularly to a centrifugal abrasive propelling machine wherein the abrasive is picked up and thrown at abrading velocity by removable abrasive propelling blades.-

This application is a division of my copending application, Serial No. 709,727, filed February 5, 1934.

According to this invention, the machine is designed and constructed 'as to protect the machine interior from the wearing effects of the abrasive as it moves through themachine, the wear from this cause being substantially confined to removable and replaceable abrasive propelling blades formed from wear-resisting metal, which can be quickly and easily removed and replaced when necessary.

It is appreciated that in centrifugal abrasive throwing machines designed to hurl abrasive at velocities suiflcient to effectively cleanmetal sheets, castings and the like, the throwing blades are subjected to severe wear, requiring periodic replacement. In accordance with this invention, the machine generally comprises a plurality of throwing blades which are generally radially arranged in' spaced relationship, which may be mounted on a rotor disc rotatably mounted on a suitable drive shaft. The blades are so mounted as to be easily and quickly removed through the periphery of the wheel or rotor, the blades preferably extending inwardly short of the axis of rotation of the rotor to provide a central space within which may be positioned an abrasive feeding device. ,The throwing blades are so arranged as to define therebetween a passage through which the abrasive discharged from the abrasive feeding device may flow, each blade providing a wear surface along which the abrasive moves or slides outwardly toward the periphery of the rotor. positioned adjacent to the feed device which discharges the abrasive onto the inner ends of the blades. A suitable feed pipe may be provided for supplying the feed device with abrasive.

It will be appreciated that, in centrifugal abrading machines of this character having a rotor diameter of approximately 19" and driven at a speed of 2250 R. P. M. so as to throw the abrasive from the periphery thereof at approximately 11,000 line'al feet per minute and upwards, wear on the moving parts is a serious problem to be contended with.

An object of this invention isto provide an abrasive hrowing machine which is so constructed that the permanent parts of the ma- The inner end of each blade is chine interior are protected from the wearing effects of the abrasive moving through the machine.

Another object of this invention is to provide a centrifugal abrading machine having means 5 associated therewith for removably retaining the abrasive propelling blades in operative position by which the blades are securely held against removal while the machine is in operation, but which nevertheless permits rapid removal and 10 replacement of the blades therefrom.

Another object of the present invention comprises the provision of an improved abrasive propelling blade constructed to maintain the outwardly moving abrasive within the confines there- 15 of, which is sturdy and lasting in construction and designed to permit easy assembly and removal from the machine.

Other objects of this invention will become apparent as the disclosure proceeds.

In order that a clearer understandingof my invention may be had, attention is hereby directed to the accompanying drawings, forming a part of this application and illustrating certain possible embodiments of the invention. Referring to the 25 drawings:

- Fig. 1 is a face view of the abrasive machine showing particularly the rotor with abrasive propelling blades mounted therein, certain parts being broken. away to more clearly illustrate the 3 construction;

Fig. 2 is a side view of the abrasive throwing machine; i

Fig. 8 is a transverse cross-sectional view through the machine, this view being taken on 35 line 3-3 of Fig. 1; and

Fig. 4 is a perspective view of one of the removable abrasive throwing blades associated with the machine.

Similar reference characters refer to similar 40 parts throughout the several views of the drawings and the specification.

According to this invention, abrasive particles, such as sand, steel grit or shot, are fed into an abrasive feeding, device centrally posi- 45 tioned within a rotor. The rotor may comprise spaced discs I and I5 joined together by suitable spacing members or webs which may comprise an advancingvane 2 and a following vane 3, having an apex portion 4 joining the vanes 2 and 3. The rotor is mounted upon a rotatably mounted shaft 5 having a hub 6 connected thereto by means of a spline 40. The hub 6 is removably connected to the disc I of the rotor by means of bolts 1.

Abrasive propelling blades b, shown more particularly in Fig. 4, made of wear-resisting material, are mounted within the rotor, each providing a confining passage for the outwardly moving abrasive. The blades b lie between the discs I and I5 and preferably extend substantially radially, as shown in Fig. 1 of the drawings. A-ny convenient number of blades may be used, an abrasive throwing machine equipped with eight blades being shown in the drawings. Each blade b extends from the outer periphery of the rotor inwardly short of the axis'of rotation thereof to provide a central abrasive admitting space a,

' within which a suitable abrasive feed device 0 may be positioned. The abrasive is fed into the feed device through a feed pipe I, the abrasive discharging into the feed device through the discharge end 65 of the feed pipe f extending into the feed device 0. The feed-device c is provided with a generally tubular side wall portion 2| which extends substantially parallel to the axis of rotation of the rotor. One or more abrasive discharge openings 23 are provided in the side wall portion 2| of the feed device, through which the abrasive is discharged and conducted across the inner ends of rapidly rotating throwing blades b. It will be noted by referring more particularly to Fig. 1 of the drawings, that the inner ends of the blades extend closely adjacent to the side wall portion H of .the feed device.

Each of the throwing blades b is'shaped in the form of a chute having a generally channelshaped transverse cross-section. Each blade comprises a bottom portion Ill and side wall portions II and I2 which protect the discs I and I5 respectively from contact with-the moving abrasive and further serve to confine the moving abrasive within and between the side wall portions and on the advancing'face of the bottom portion III of the blade. The blades b are removably secured within the rotor in such a manner that they may be removed through the rotor periphery without in any way dismantling the rotor. The disc member I may be provided with a projecting shoulder I6 adapted to seat within a groove l3 cut in the side wall II of the blade b. A set screw I4 is screwed through the disc member IS, with the inner tapered ends Ila of the set screw abutting against the side wall portion I l of the blade to lock the blade in operative position. It will be noted by referring to Figs. 1 and 3 of the drawings that the set screw I4 has the outer end thereof substantially flush with or seating within the outside face of the rotor disc I5, the set screw being provided with an internal tool-receiving socket Mb into which a screw driver or other tool may be inserted to manipulate the screw.

Either one or both ends of the bottom wall portion I0 and the side wall portions .II and I2 of the blade may be tapered, as shown more particularly in Figs. 1, 3 and 4 of the drawings so as to cause a minimum obstruction to the entry of abrasive onto the inner ends of the blades as it is discharged from the discharge openings 23 in the feed device .0. The blades as shown in Figs. 1 and 3 of the drawings are truly symmetrical so that the blades may be turned end for end in the rotor. Thus either end may be positioned adjacent the feed device 0. Since the abrasive is moving over the advancing face of the bottom wall portion I0 of the blades at a greater velocity at the outer end than at the inner end of the blades positioned within the rotor. the advancing face of the bottom wall portion III at the outer end is more severely worn than the inner end. Thus by making the blades reversible end for end, the inner end, which has been only slightly worn after the blade has been in use, may be positioned adjacent the rotor pe- 6 riphery where the abrasive wear is more severe, thus permitting the blade to be continued in service for an additional period.

As shown more particularly in Figs. 2 and 3, the discs I and I5 may be provided with heavy rim portions which extend a substantial distance inwardly, which serve to balance the rotor and steady the rotating movement thereof. The rim portions I8 may be cut away to provide guideways I9 into which the side edges of the blades b extend, as shown more particularly in Fig. 2. It will be evident by referring to Figs. 1, 2 and 3 that the blades may be withdrawn outwardly through the rotor periphery and through the ggidewa-ys I9 upon manipulation of the set screw The abrasive discharge opening or openings 23 in the feed device 0, as shown in Figs. 2 and 3, are of less width than the distance between the spaced discs I and I5 and are so shaped and arranged that the abrasive when discharged is conducted directly onto the advancing face of the propelling blades b and is given little opportunity to contact the sides of discs I and I5 so as toappreciably wear the same. It will be further noted by referring more particularly to Fig. 3, that the inside faces of the side wall portions II and I2 of the'blade flare outwardly as at I! toward the adjacent end of the blade so as to more readily catch the abrasive admitted from the discharge opening or openings 23 in the feed device 0. Thus the abrasive moving through the machine at abrading velocities is confined within the flanges or side wall portions II and I2 of the blades and is substantially kept out of abrasive contact with the permanent parts of the rotor.

In a centrifugal abrasive machine as thus constructed there is little wear on the permanent parts'of the machine and the abrasive wear is substantially confined to the advancing face of the blades b,'which blades can be relatively inexpensively made and can be easily and quickly replaced when worn.

The abrasive propelling blades designed as above described to contain the outwardly moving abrasive within the flange confines thereof, give a long wear life, are so constructed as to receive the abrasive from .the feeding device with the minimum friction and interference, and are easily removable and replaceable when worn out.

While certain novel features of the invention have been disclosed herein, and are pointed out in the annexed claims, it will be understood that various omissions, substitutions and changes may be made by those skilled in the art without departing from the spirit of the invention.

What is claimed is:

1. In an abrading machine, a rotor embracing spaced side wall members mounted for rotation, an abrasive propelling blade mounted between said side wall members and having a propelling surface facing forwardly with respect to the direction of rotation and operable to pick up the abrasive and discharge it at an abrading velocity, "u said blade being substantially symmetrical and having a notch in each side edge thereof for selectively securing it to one of said side wall members, whereby said blade may be reversed end for end in said rotor.

bladed abrasive propelling rotor, an abrasive prosenting a substantially flat outside pelling blade having a bottom wall providing an abrasive propelling surface adapted to face forwardly with respect to the direction of rotation of the rotor, said blade having abrasive-confining side walls at each side edge and along the abraslve propelling surface thereof, said blade having a recess in each side edge thereof so positioned that one of said recesses will cooperate with a relatively fixed securing element associatedwith said rotor irrespective of the end to end position of said blade in the rotor, each end of said blade being tapered so as to assist entry of the abrasive onto the end of the blade when either endis positioned inwardly of the rotor.

3. For use in a centrifugal abrading machine embracing spaced side wall members having means associated therewith for supporting a plurality of abrasive throwing blades therebetween, an abrasive propelling blade having a bottom wall portion and a pair of similar spaced substantially parallel extending abrasive confining side wall portions, each of said side wall portions being of uniform height substantially throughout the entire length thereof, said bottom wall portion pre surface coplanar with the lower edges of said side wall portions, said bottom wall portion having a tapered end to facilitate entry of the abrasive ontothe abrasive receiving face of said bottom wall portion, the inside faces of said side wall portions flaring outwardly adjacent the tapered end, and a notch provided in the exterior face of one of said side wall portions adapted to receive a blade securing element.

4. In an abrading machine, in combination, a rotor'head embracingspaced side wall discs, means connecting said discs in fixed spaced relationship, a plurality of rigid abrasive propelling blades positioned between and supported by said side wall discs, each of said blades having a bottom wall portion and a pairof similar spaced substantially parallel extending abrasive confining side wall portions, each of said side wall portions being of uniform height substantially through the entire length thereof, said bottom wall portion having a substantially flat outside surface co-planar with the lower edges of said side wall portions, one end of said blade being tapered so as to facilitate entry of abrasive onto the abrasive receiving face of said bottom wall portion, each of said side Wall portions having a notch provided in the exterior face thereof adapted to receive a blade securing element.

5. For use in an abrading machine having a bladed abrasive propelling rotor, an abrasivepropelling blade of elongated generallyflat configuration, said blade having an abrasive-confining side wall along each side edge thereof, said blade having an abutment portion along each side edge thereof adapted to cooperate with means associated with said rotor for securing the blade to the rotor, said blade being reversible end for end in said rotor. I

6. For use in a centrifugal abrading machine embracing a rotor head comprising spaced rigidly connected side wall members arranged to support a plurality of abrasive throwing blades therebetween, a cast metal blade comprising a bottom wall portion and a pair of similar spaced substantially parallel extending abrasive confining side wall portions, each of said side wall portions being of uniform height substantially throughout the entire length thereof, said bottom wall portion having a substantially flat inside abrasive receiving surface from which said side wall porjtions rise substantially perpendicular thereto and a substantially flat outside surface substantially .co-planar with the lower edges ofsaid sidewall portions, one end of said blade being tapered so as to facilitate entry of abrasive onto the abrasive receiving face of said bottom wall portion, the exteriori'ace of each of said side wall portions having diagonally arranged blade securing abutments.

7. In an abrading machine, a rotor mounted for rotation, an abrasive propelling blade operably associated with said rotor and having a propelling surface facing forwardly with respect to the direction of rotation and operable to pick up the abrasive and discharge it at abrading velocity, said blade being substantially symmetrical, and an element extending through an aperture in said rotor for securing said blade to said rotor,

said element being operable to cooperate with either side edge of the blade, whereby said blade may be reversed end for end in said rotor.

8. For use in a centrifugal abrasive throwing rotor head, a rigid abrasive propelling blade formed of wear resistant metal embracing a bottom wall portion and a pair of similar spaced substantially parallel extending abrasive confining side wall portions, each of said side wall portions being of uniform height substantially throughout the entire length thereof, said bottom wall portion having a substantially flat inside abrasive receiving surface from which said side wall portions rise substantially perpendicular thereto and a substantially flat outside surface substantially co-planar with the lower edges of said side wall portions, one end of said blade being tapered so as to facilitate entry of abrasive onto the abrasive receiving face of said bottom wall portion, the exterior face of each of said side wall portions having a blade securing notch therein.

9. For use in an abrading machine having a bladed abrasive propelling rotor, an abrasive propelling blade having a bottom wall providing an abrasive propelling surface adapted to face forwardly with respect to the direction of rotation of the rotor, said blade, being designed for reversible end for end positioning in the rotor, said blade having abrasive-confining side walls at each side edge and along the abrasive propelling surface thereof, and a recess in each side edge of said blade so positioned that one of said recesses will cooperate with a relatively fixed securing element associated with said rotor irrespective of the end for end position of said blade in the rotor.

10. An abrasive propelling blade foruse in a centrifugal abrasive throwing rotor of the type having a pair of spaced side wall members adapted to carry one or more abrasive propelling blades arranged radially therebetween, said blade being formed of cast metal of wear resistant properties having a substantially straight bottom wall portion defining an inner abrasive supporting surface having one end thereof tapered to provide a relatively thin edge, similar abrasive guiding and confining side wall portions of substantially uniform height extending along the sides of said bottom wall portion, the inside surface of each of said side wall portionsadjacent the tapered end of the bottom'wall portion diverging outwardly to facilitate entry of abrasive a notched recess in the exterior surface thereof each defining spaced abutments adapted to receive a blade locking element.

' 11. A reversible substantially symmetrical abrasive propelling blade for use in a rotor of the type having spaced generally parallel side wall members carrying one or more abrasive propelling blades generally radially therebetween, said blade being formed of rigid wear resistant metal embracing a substantially straight bottom wall portion and substantially parallel extending similar side wall portions for confining the abrasive upon said bottom wall portion, said side wall portions being of substantially uniform height substantially throughout the entire length thereof, and an abutment in the exterior surface of each of said'side wall portions sopositioned that one of said abutments will cooperate with a relatively fixed securing element associated with said aaoaoaa rotor irrespective of the end-for-end position of said blade in the rotor.

12. A reversible abrasive propelling blade for use in a rotor of the type having spaced generally parallel side wall members carrying one or more abrasive propelling blades generally radially therebetween, said blade being formed of rigid wear resistant metal embracing a substantially straight bottom wall portion and substantially parallel extending side wall portions for confining the abrasive upon said bottom wall portion, said side wall portions being of substantially uniform height substantially throughout the entire length thereof, and a notch in the exterior surface of each of said side wall portions so positioned that one of said notches will cooperate with a relatively fixed securing element associated with said rotor irrespective of the end-forend position of said blade in the rotor.

. DAVID C. TURNBULL. 

